Loud-speaking telephone receiver



22 1 Margh 927 H. KOCH LOUD SPEAKING TELEPHONE RECEIVER Filed March 30, 1925 MW e I N VEN TOR HEW/H If 06/! ATTORNEYS.

- latented Mar: 22,1927.

UNITED s ATnsPATENT OFFICE.

HENRY x0011, or.

alimarcmnnw YORK, ASSIGNOR '10 mcroen'arn rnonoo'rs con ronnrro r, A CORPORATION or vrnerma.

nonn-srnnxme TELEPHONE nnonrvnn.

' relatively to one another, and with any given spacing of the diaphragm and pole pieces the instrument might operate well when connected in one receiving set, and'unsatisfactorily when connected in another receiving set or when the voltage and current conditions in the circuit were varied. An ob ect of the lnvention 18 to provide an improved receiver of this type which,

may be operated successfully and satisfac- =Ltorily with any receiving set or'instrument, or under various conditions of current and voltage, and which is relatively simple in construction and operation, and inexpensive. Other objects .and advantages will be apparent from the following embodiment ofthe invention and the novel features will be particularly pointed out hereinafter in claims. J

' In theaccompanying drawing? Figure 1 is a sectional elevation of an instrumen-t constructed in accordance with the invention;

Figure 2 is a transverse sectional elevation of the same, the line 2-2 of Fig. 1;-

Figure 3 is a sectional plan of the same taken substantially along the. line 33 of Fig. 1; and Y Figure 4 isatransverse sectional elevation of the sameytaken substantially along the line 4-4 of Fig. 1.

In the illustrated embodiment of the in- 4 vention, an amplifying horn 1.is mounted .upon oneend of a suitable casing 2 so as to communicate at its small end with the. in terior of the casing through an aperture 5 in one of the casing walls. A disc 4 over- 1 lies the'aperture 3 and is secured to the inner face of the casing in any suitable manner such as by means of screws 5 which extend from the base of the disc through apertures 6 in the casing and through apertures telephone receiving sets .ingends of the screws 5 flanged end 8 of the amplifying horn to the ture 12, -aligned with the with the passage at the smallend of the ami 70 description of an taken substantiallyealong ion or teeth.26 teeth of the gear 22, so that when the shaft Application filed March 30, 1923.. Serial No. 628,709.

7 in the flange 8 provided upon the small or inlet end of the amplifying horn. A nut 9 is t readed upon each screw 5 between the flange 8 and the wall of the casing, being countersunk into a recess 10 in the outer face of the casing so as to allow theflange 8 to abut tightly against the outer surface of the casing. The nut 9 serves to hold the disc 4 to the-inner face of the casing before the amplifier is applied to the casing over the projecting ends of the screws 5 Nuts 11 may be threaded upon the extreme project so as to clamp the casing; The amplifying hornis thus supported firmly at its small end, but'ob'viously may also be supported at other points if desired. The disc 4 is provided with an aperplifying horn.

aperture 3 and.

A frame 13 having an aperture 14 in one face thereof is secured in a suitable manner, such'as by screws 15, to the exposed face of the disc 4 soas to clamp between them a suitable dia hragm 16, the diaphragm being clampe around its periphery. The frame is provided with extensions 17 which are connected at their rear ends by a bar 18 extending parallel to the I tured end of the frame. The bar 18 is provided with an aperture 19 aligned with the aperture 14 of the frame. rotatably and slidably mounted in the aperture 14, and carries an axial extension21 whicli passes through the aperture 19 of the bar 18 and has threaded engagement therewith, so that 'when the barrel 20 is rotated it will be given a somewhat axial movement owing to its threaded engagement with the cross bar 18 of the frame. A gear 22 is secured, in any suitable manner such as bv screws 23, to the barrel 20. I

An actuating shaft 24 is rotatably'mounted in an'aperture 25 of the cross bar 18, at one side of the aperture 19, and carries pinwhich mesh with the gear 24 is rotated in the aperture 25, the pinion plane of the aper-f A barrel 20 is 7 or teeth 26 of the shaft will drive the ear 22 and through it rotate the barrelv 20. The barrel in rotating will, as before explained, move slightly in an axial direction because of its connection to the frame; The

- shaft 24 extends through'a wall of the casing and carries at its outer end 'a suitable operatin handle or knob 27 and dial 28 by which t e rotation of the shaft may be I manually accomplished and the increments of rotation measured. The knob and dial abut against the outer face of the casing and a suitable washer 29 and cotter pin 30 may be provided upon the shaft within the easing so as to abut against the inner face of the Wall of the casing through which the shaft passes. Theshaft is thus .held against endwise displacement but is free to rotate.

One of the teeth 26 of the shaft which is indicated by the reference character 26 (Fig. 2) is considerably wider than the other teeth and is too wide to pass in the space between the two adjoining teeth of the gear 22, so that whenever this tooth engages with the teeth of'thegear 22, further rotation in thesame direction will be prevented. This tooth 26 therefore acts as a limit stop for limiting rotation of the shaft in any suitable manner to the exterior of the cuit.

In order to hold the barrel in different angular positions to which it has been rotated, I ma secure leaf springs 32 to the extensions 1% by screws 33, so as to extend between the extensions and around and in contact with portions of the periphery of the barrel. By tightening the screws 33 the casing for connection to an operating cirsprings 32 can be carried into closer proximity to the extensions so as to press more firmly against the barrel periphery and thus I create a greater frictional resistance to rotation of the barrel. By loosening the screws 33, the frictional resistance to rotation of the barrel maybe lessened.

In use the device is assembledin the manner indicated, and the wires 30 are connected to a'suitable operating circuit such as the plate circuit of a radio telephone receiving apparatus. The knob 27 is then rotated until the maximum loudness and clearness of sounds coming from .the amplifying horn 1 are secured. The rotation of. the knob serves to shift the barrel 20 endwise, whichcarries the poles 29 toward or from thediaphragm to vary their influence thereon. The springs 32 frictionally hold the barrel in the difierent adjusted positions and the tooth 26 confines the rotation of the barrel to be adjusted to operate successfully and give practical limits. The instrument'may thus Y maximum loudness and clearness of sounds when connected in any receiving set, and under all conditions of voltage and current which are likely to. be encountered in operating circuits.

Itwill be obvious that various changes in i the details and arrangements of parts herein described and illustrated for the purpose of explaining the nature of the invention,

may be made by those skilled in the art within the principle and scope of the invention as expressed in. the appended claims. W I claim: a 1. A telephone receiver comprising a dia phragm support, a diaphragm mounted therein, an electromagnetic device mounted for rotation relative to said diaphragm support, a screw threaded connection between thediaphragm-support and the electromagnetlc device whereby upon rotation of the electromagnetic device the diaphragm and said device will be relatively adjusted toward or from each other, axially rotatable actu-' ating means, and gear connections between said means and said electromagnetic device whereby axial rotation of said means effects rotation of the electromagnetic device.

2. A telephone receiver comprising a sound wave amplifier, a frame supported adjacent the inlet end of the amplifier, a diaphragm disposed in a position to set up sound waves in the inlet end of the amplifier, an electromagnetic device rotatably carried. by the frame in proximity to the diaphragm to actuate the same, said device having threaded engagement with the frame, whereby as the device is rotated it will be carried bodily to ward or from the diaphragm to vary its influence thereon, axially rotatable actuating means, and gear connectlons between said means and said electromagnetic device whereby axial rotation of said means effects.

rotation of the electromagnetic device.

3. A telephone receiver comprising a sound wave amplifier, a frame supported adjacent the inlet end of the amplifier, a diaphragm disposed in a position to set up sound waves in the inlet end of the amplifier, an electromagnetic device rotatably carried by the frame in proximity.to the diaphragm to actuate 'the same, sa1d device having threaded engagement with the frame, whereby as the device is rotated it will be carried bodily to-- ward or from the diaphragm to vary its influencethereon, an operating member, and a geared connection between the member and the electromagnetic device, whereby the elec-' tromagnetic device may be rotated to vary the position of the electromagnetic device relatively to the diaphragm.

4. A telephone receiver comprising a sound wave amplifier, a frame supported adjacent the inlet end of the amplifier, a diaphragm disposed in a position to set up sound waves in the inlet end of the amplifier, an electromagnetic device rotatably carried by the frame in proximity to the diaphragm to actuate the same, said device having threaded engagement with the frame, whereby as" the device is rotated it will be carried bodily toward or from the diaphragm to vary its influence thereon, a gear member rotatable unitarily with said electromagnetic device with gear teeth extending .arcuately about its axis of rotation, and a shaft having on one end an operating button and carrying thereon a gear member meshing with the gear teeth of the other gear member, whereby the electromagengagement with the frame,

,netic device maybe rbtated to vary the pa, sition ofthe electromagnetic device .relative to the diaphragm.

5. A telephone receiver comprising a sound wave amplifier, a frame su ported adjacent the inlet end of the ampli er, a diaphragm disposed in a position to set u sound waves in the inlet end of the ampli er, an electro- -magnetic device rotatably carried by the frame in proximity to the diaphragm to actuate the same, said device having threaded whereby as the device is rotated it will be carried bodily toward or from the diaphragm to vary its influence thereon, a gear member, 6n said electromagentic device with gear teeth extendingarcuately about. its axis of, rotation, and a shaft having on one end. an operating button and carrying thereon a gear member meshing with the gear teeth of the other gear member, whereby the position of the electromagnetic device relatively to the diaphragm m'aybe varied by operation of the button, one

. of the gear members having a tooth of greater width thanthe distance between two teeth whereby when it is engaged by the teeth of the other'gear member it acts as a limit stop to limit the adjustment of the electromag-' netic device. r J I 6. A telephone receiver comprising two relatively rotatable parts, one of said pagts comprising a diaphragm support and a d1aph'ragm mounted therein and the other of' said parts: comprisin an electromagnetic device for actuating t e diaphragm, a screw threaded connection between said parts whereby upon relative rotation between the parts the electromagnetic device and diaphragm support maybe adgusted relatively. toward or ro'm each other, axially rotatable actuating means, and" gear connections whereby axial rotation of said means rotates.

carried by one of said parts and efl'ects adjustment of the diaphragm and electromagnetic device toward or from each other. I j

7 A telephone receiver comprising two relatively rotatable parts, one of said parts comprising a diaphragm support and adiaphragm mounted therein and the other of said parts comprising an electromagnetic de vice for actuating the diaphragm, a screw threaded connection between said parts whereby-upon relative rotation between the parts the electromagnetic device and diaphragm support may-be adjusted relatively I toward or m n each other, axially rotatable actuating means, and gearing nnections whereby axial rotation of said means rotates one of said parts and effects adjustment of the diaphragm and electromagnetic device it toward or from each other.- 8. The receiver substantially as set forth in claim 7 in which one of the members'of' the gearing connection has a tooth. ofgrea'ter width than the others to act as a limit stop when it engages the other member of the connection. i

9. A telephone receiver, a soundwave amplifier, a diaphragm disposed ina osition to set up sound waves invthe inlet 'en of the amplifier, a support for the diaphragm, an electromagnetic device operative u on the diaphragm to actuate'the same an having a screw-threaded;connection with the support whereby upon relative rotary movement the device and diaphragm may be adjusted relatively toward and from one. another, means for producing movement, and a spring friction element one" of the relatively .rotating parts and engaging with the other whereb these parts will be .frictionally held in di ferent relative positions. a

10.;A telephone receiver, a sound wave,

such relative rotary amplifier, a diaphragm disposed in a posi-' tion' to set up sound waves in the ofthe amplifier, Ph es upon the having a screw-threaded connection with the support whereby upon relative rotary movement the device justed relativel toward an other, means or producin inlet end a support for the diafrom one ansuch relative and-diaphra m'may be ad\ an electromagnetic device operative diaphragm to actuate the same and rotary movement, and a spring friction element adjustably carried by one of the relatively rotating parts and. engaging with the other whereb these parts will-be frictionally held in ifi'erent relative positions.

113A telephone receiver, a sound wave amplifier, a diaphragm disposed in a position to set up sound waves in the inlet end of the amplifier, a sup an electromagnetic evice operative upon the diaphragm to 'actuatethe same and having a screw-threaded.connection with the supg port whereby upon relative rotary moveiao ort for, the diaphragm,

ment the device and diaphragm may be ad.- ment to vary the pressure of the spring on the justed relatively toward and from one andevice, whereby the relativel rotating parts 1 other, means forproducing such relative rowill be frictionally held in ifierent relative tary movement, a leaf spring bridged across positions.

5 spaced points on the diaphragm support and In 'witness whereof, I hereunto subscribe in frictional contact with the e1ectromagmy signature. netic device, and means for securing the spring to the support and capable of adjust HENRY KOCH. 

